The present invention relates to signal processing apparatuses and methods and to recording media and programs for controlling the signal processing apparatuses and methods, and more particularly, to a signal processing apparatus and method capable of generating high-quality images and to a recording medium and a program for controlling such signal processing apparatus and method.
Recently, due to an increase in the size of display screens for television receivers, images often have been displayed using image signals having a large number of pixels. Thus, for example, processing for converting pixels into quadruple-density pixels in order to convert standard-definition (SD) images into high-definition (HD) images is suggested, for example, in Japanese Unexamined Patent Application Publication No. 2000-78536. Thus, viewers can view higher-quality images on large screens.
However, when an output image is generated using a linear prediction coefficient, a unique output image is determined from an input image. In addition, for example, when a method is adopted for performing classification by adaptive dynamic range coding (ADRC), for reading an optimal prediction coefficient from among prediction coefficients learned in advance in accordance with the classification, and for generating an output image in accordance with the prediction coefficient, a unique output image is determined depending on the input image. Although in order to reduce the error between an input image and an output image, a prediction coefficient is generated by learning many supervisor images in advance, the error may not be satisfactorily reduced for some input images.
In such cases, the high-resolution images that are generated have been output as they are. For example, by quadruple-density conversion, four pixels are generated from one pixel using respective independent linear prediction coefficients. Since the characteristics of the processing performed between the four pixels are different from the characteristics of the processing performed between another four pixels acquired from another input pixel, discontinuity may occur.
As a result, users may not be able to view images with high quality.